Steam-engine valve



(No Model.)

H. H. WESTINGHOUSE 8v W. A. BOLE.

STEAM ENGINE VALVE.

No. 329,347. Patented Oct. 27, 1885.

NVENTOR'.

ATTO/@NE TER Phomlimagnphunwmhin Nrrn TATES PATENT trice.

H. HERMAN TWESTINGHOUSE, OF NEV YORK, N. Y., AND WILLIAM A. BOLE, OF PITTSBURG, PENNSYLVANIA, ASSIGNORS TO THE WESTINGHOUSE MACHINE COMPANY, OF PITTSBURG, PENNSYLVANIA.

STEAM-ENGINE VALVE.

SPECIFICATION forming part of Letters Patent No. 329,347, dated October 27, 1885.

Application filed August 15, 1885. Serial No. 174,476.

To @ZZ whom it may concern:

Beit known that we, H. HERMAN WEsTING- HoUsE, residing at New York, in the county and State of N ew York, and NVILLIAM A. BoLE,

residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, both citizens ofthe United States, have jointly invented or discovered certain new and useful Improve mentsin Steam-Engine Valves, of which imxo provements the following is a specification.

In the accompanying drawings, which make part of this specication, Figurel is a vertical central section through a steam-engine distribution-valve and its chest or chamber, illustrating the application of our invention, and Fig. 2, a transverse section through the same at the line a: :v of Fig. 1.

Our invention relates to steam-engine distributionyalves of the piston type, and is 2o more particularly designed for application to single-acting engines of the class in which a pair of cylinders is located above a closed crank-case, the functions of steam admission, exhaust, and cut-off being performed by a distribution-valve common to both cylinders, an instance of which is exemplified in Reissued Letters Patent No. 10,603, granted and issued to The Xlfestinghouse Machine Company, as assignee of H. H. Vestinghouse, May 26, 1885.

The object of our invention is to perfect the balancing of a valve of such character by the equalization of pressure thereon, and to relieve the valve-chest from leakage and Water of condensation.

To this end our invention, generally stated, consists in the combination, with a tubular valve having an open-ended piston at each of its ends, of a guide-piston and asupplemental back-pressure piston corresponding in area 4o and working,respectively, in opposite ends of the valvevcasing; also, in the combination of a valve as described, a valve chest or chamber, and arelief-passage leading from the upper end of the valve-chamber to a suitable 45 point of discharge.

rlhe improvements claimed are hereinafter fully set forth.

The distribution-valve 12, herein selected for illustration, is, as in Reissued Letters Pat- (No model.)

ent N o. 10,603, before referred to, composed 5o of an `upper pistou, 38, and a lower piston, 39, connected by a hollow or tubular body portion, and secured upon a valve-stem, 16, to the lower end of which is connected a guidepiston, 17, working in an open-ended guidecylinder, 18, projecting downwardly from a transverse partition in the valve chest or chamber 3, above a closed crank-case, 2. The valve is reciprocated by an eccentric-rod, 19, coupled to a pin fixed to the guide-piston 17, and Works 6o in a sleeve or bushing, 40, in the valve-cham ber 3. Steam is supplied to the valvechamber and to the space between the main pistons 38 39 of the valve through a steam-supply nozzle, 11, and, by the movements of the valve, is alternately admitted to and exhausted from two single-acting cylinders, 1 1, located on opposite sides ofthe valve-chamber, through ports 13 and 14, respectively, the exhaust being effected through the center of the valve, 7o and from the space below its lower piston, 39, into an exhaust passage or nozzle, 15, to which the exhaust-pipe is connected. The upper end of the casing of the valve is closed by a tight head or bonnet, 64, and the lower by the guide-piston 17; and it will be seen that the valve is subject to steam-pressure between its pistons 38 39, (which pressure is balanced, as said pistons are of equal areas,) and to the back-pressure of the exhaust upon its inner 8o surface and upon the area of the guide-piston 17. Under the construction employed prior to our invention, as shown in Reissue 10,603, such pressure upon the piston 17 was unbalanced, the valve being open at its upper end to the space closed by the head 64. To obviate this cbj ection,and thereby effect an equalization of exhaust-pressure upon the Valve, a supplemental back-pressure piston, 62, corresponding in area with the guide-piston 17, is 9o secured upon the valve-stem 16, adjacent to the upper valve-piston, 38, said piston fitting truly and working with the valve and valve` stem in the bushing 40 of the valve-chamber. Equal pressure in opposite directions being thus exerted by the exhaust upon the pistons 17 and 62, the valve will be perfectly balanced as against back-pressure, the advantage of which is specially important in automatic cut-ofi` engines in relieving the governor and movable eccentric from the disturbing action which would otherwise tend to be exerted upon them twice in each revolution of the engine by unbalanced back-pressure upon the guide-piston of the valve.

In order to carry off any exhaust-steam leakage or water of condensation that may gain access to the space between the supplemental piston 62 and the head 64 of the valvechamber, as well as to prevent resistance to the movement of the valve by compression in said' space, a relief-passage, 63, is formed in the wall of the valve-chamber 3, said passage opening into the chamber above the level of the piston 62, when at the upper extremity of its traverse, and leadingv therefrom to the crank-case 2, or to any other suitable and convenient point of discharge. In the instance shown the upper portion of the passage 63 is formed by drilling at right angles into the casting, the -outer ends of the holes being closed by proper plugs, and the lower portion consists of a pipe which may be either set in the mold and the metal of the valve-chamber cast partially around it, or may be connected to the valve-chamber after the upper portion of the` passage has beenv formed therein.

We claim herein as our inventionl. 'Ihe combination of a steam-engine valve having two end pistons connected by a tubular body, a guide-piston and a supplemental back-pressure piston corresponding, substantially, in area and secured upon opposite ends of the stem of the valve, a valvechamber having a closed head at one end and an openended guide-cylinder at the other and ports governed by the end pistons of the Valve, a steam-passage opening into the valve-chamber between the end pistons of the valve, and an exhaust-passage leading out of the valvechamber between an end piston of the valve H. H. WESTINGHOUSE. WILLIAM A. BOLE.

Witnesses as to H. H Westinghouse: J .y SNOWDEN BELL, G. W. WILLIAMS. Witnesses as to Wm. A. Bole:

J. SNowDEN BELL, C. M. CLARKE. 

